Sound intensity level or acoustic intensity level is a logarithmic measure of the sound intensity (measured in W/m2), in comparison to a reference level.
The measure of a ratio of two sound intensities is
where I1 and I0 are the intensities.
The sound intensity level is given the letter "LI" and is measured in "dB". The decibel is a dimensionless quantity.
If I0 is the standard reference sound intensity
(W = watt), then instead of "dB SPL" we use "dB SIL". (SIL = sound intensity level).
Read more about this topic: Sound Intensity
Famous quotes containing the words sound, intensity and/or level:
“Al: Ain’t you gonna look back, Ma? Give the old place a last look?
Ma Joad: We’re goin’ to California, ain’t we? Alright then, let’s go to California.
Al: That don’t sound like you, Ma. You never was like that before.
Ma Joad: I never had my house pushed over before. Never had my family stuck out on the road. I never had to lose everything I had in life.”
—Nunnally Johnson (1897–1977)
“Murder is born of love, and love attains the greatest intensity in murder.”
—Octave Mirbeau (1850–1917)
“Preschoolers sound much brighter and more knowledgeable than they really are, which is why so many parents and grandparents are so sure their progeny are gifted and super-bright. Because children’s questions sound so mature and sophisticated, we are tempted to answer them at a level of abstraction far beyond the child’s level of comprehension. That is a temptation we should resist.”
—David Elkind (20th century)